Apparatus for adjusting the height of a tool such as a lawnmower, particularly for gardening vehicles

ABSTRACT

Apparatus for adjusting the height of a tool particularly for gardening vehicles, comprising front wheels whose height can be adjusted on corresponding supports that are rigidly coupled, at the front, to a housing suitable to form the chassis of the tool, the apparatus comprising:  
     a rear linkage, which is articulated in a lower region with respect to the protective housing of the tool,  
     a crank arranged above the housing along the tool advancement direction, with a front end articulated above the housing and a rear end articulated to the upper end of the linkage, which is rigidly coupled to a support articulated to the chassis of the vehicle, the articulation points of the linkage and the crank and the common axis of rotation of the wheels providing the joints of an articulated quadrilateral constituted by the housing, the linkage, the crank and the wheel supports.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an apparatus for adjusting theheight of a tool such as a lawnmower or the like, particularly forgardening vehicles.

[0002] As is known, vehicles are currently used, especially in the fieldof small or large garden maintenance, which can have a structure that isdedicated to a specific function and therefore are only lawnmowers, orcan be constituted by a tractor that supports tools interchangeably.

[0003] In the particular case of lawnmower tools, the tools areconstituted by a protective housing, which acts as a chassis, supports aplurality of blades arranged substantially horizontally, and is providedwith four wheels whose height can be adjusted in order to consequentlyadjust the height of said housing from the ground, determining thecutting height.

[0004] The housing is associated with a supporting arm, in which one endis articulated to the vehicle and one end is rigidly coupled to thehousing.

[0005] Although having a widespread use, these tools of the lawnmowertype are not devoid of drawbacks.

[0006] Particular difficulty is in fact encountered in adjusting theheight of the housing from the ground in order to determine the cuttingheight of the tool.

[0007] The adjustment is in fact performed by acting on each wheel, oneat a time.

[0008] The operation is therefore particularly slow and complicated.

SUMMARY OF THE INVENTION

[0009] The aim of the present invention is to provide an apparatusparticularly for adjusting the height of tools such as lawnmowers or thelike for gardening vehicles that solves the drawbacks of conventionallawnmower tools.

[0010] Within this aim, an object of the invention is to provide anapparatus that allows quick adjustment of the height of the tool.

[0011] Another object is to provide an apparatus that can be used evenby users lacking particular technical knowledge.

[0012] Another object is to provide an apparatus that has a simplestructure.

[0013] Another object is to provide an apparatus that has a low cost andcan be manufactured with conventional equipment and technologies.

[0014] This aim and these and other objects that will become betterapparent hereinafter are achieved by an apparatus for adjusting theheight of a tool such as a lawnmower particularly for gardeningvehicles, of the type that comprises front wheels whose height can beadjusted on corresponding supports that are rigidly coupled, at thefront, to a protective housing suitable to form a chassis of said tool,characterized in that it comprises:

[0015] a rear linkage, which is articulated in a lower region withrespect to said protective housing of the tool,

[0016] a crank whose length can be adjusted by a user, said crank beingarranged above the housing along the tool advancement direction, with afront end that is articulated in an upper region with respect to saidhousing and a rear end that is articulated to an upper end of said rearlinkage;

[0017] said linkage being rigidly coupled to a support that isarticulated to the chassis of said vehicle, articulation points of saidlinkage and said crank and a common axis of rotation of said wheelsproviding joints of an articulated quadrilateral constituted by saidhousing, said linkage, said crank and said supports.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further characteristics and advantages of the present inventionwill become better apparent from the following detailed description of apreferred but not exclusive embodiment thereof, illustrated only by wayof non-limitative example in the accompanying drawings, wherein:

[0019]FIG. 1 is a partially sectional side view of a gardening vehiclethat is provided, in a front region, with a tool such as a lawnmower,which is provided with an apparatus for height adjustment according tothe invention;

[0020]FIG. 2 is a partially sectional side view of a tool such as alawnmower;

[0021]FIG. 3 is a partially sectional plan view of a tool such as alawnmower;

[0022]FIG. 4 is a view of a component of the apparatus according to theinvention;

[0023]FIGS. 5 and 6 are partially sectional side views of a tool such asa lawnmower provided with an apparatus according to the invention in twodifferent operating configurations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] With reference to the figures, an apparatus for adjusting theheight of a tool such as a lawnmower or the like, particularly forgardening vehicles, is generally designated by the reference numeral 10.

[0025] The apparatus 10 is associated with a lawnmower tool 11, which isarranged in front of a gardening vehicle, generally designated by thereference numeral 12.

[0026] The lawnmower tool 11 comprises a protective housing 13, whichacts as a chassis and supports, within its own dimensions, a pluralityof motorized blades 14 that are arranged substantially horizontally.

[0027] At the front, the housing 13 is provided with monolithicallycoupled supports 15 for wheels 16 for advancing on the ground.

[0028] In particular, the wheels 16 are rotatably coupled to forks 17that are rigidly coupled to substantially vertical stems 18, which slideon the tubular supports 15 and can be fixed thereon in a position whoseheight can be adjusted.

[0029] To the rear of the housing 13 there is a linkage 19, which isarticulated to the housing 13 in a lower region.

[0030] As shown in FIG. 4, the linkage 19 is constituted by a lowerportion 29, which is shaped like an inverted U and has ends 30 that arearticulated to the housing 13 about a substantially horizontal axis, andby an upper fork-shaped portion 31.

[0031] Two tubular elements 32 protrude, monolithically with respect tothe linkage 19, from the lower portion 29, above the ends 30 and in theopposite direction with respect to the housing 13; the front ends ofcorresponding rod-like elements 20 engage on the tubular elements, suchrod-like elements being also tubular and being mutually rigidly coupledand parallel, their rear ends being articulated in a lower region withrespect to the chassis of the vehicle 12.

[0032] In practice, the rod-like elements 20 form a support for the rearportion of the housing 13.

[0033] Above the housing 13 there is a crank, generally designated bythe reference numeral 22, which has a front end 23 that is rotatablycoupled to a first cylindrical joint 24 arranged at the upper portion ofan upright 25 that rises from the front portion of the housing 13, and arear end 26 that engages, with a screw-and-nut coupling, on a secondcylindrical joint 27, which is arranged above the upper portion 31 ofthe linkage 19.

[0034] At the front, the crank 22 is provided with a handwheel 28 thatis available to the user and actuates the rotation of the crank aboutits own axis.

[0035] The crank 22 is arranged along the advancement direction of thetool 11 in a substantially central position of the tool.

[0036] In practice, the articulation points of the linkage 19 and of thecrank 22 and the common axis of rotation of the wheels 16 provide thejoints of an articulated quadrilateral constituted by the housing 13,the linkage 19, the crank 22 and the supports 15 of the wheels 16, inwhich the length of the crank 22 can be adjusted by the user.

[0037] By acting on the handwheel 28, the crank 22 is turned,consequently actuating the translational motion of the secondcylindrical joint 27 along the rear end 26 of the crank 22.

[0038] In this manner, the linkage 19 rotates with respect to the axisof articulation to the housing 13 and, by cooperating with the rod-likeelements 20, actuates the lowering or lifting of the rear portion of thehousing 13 with respect to the ground.

[0039] Once a chosen height from the ground of the front portion of thehousing 13 has been reached by adjusting the height of the wheels 16, tobring the housing 13 to a trim that is substantially horizontal to theground, it is sufficient to compensate for the difference in level byacting on the handwheel 28, thus actuating the necessary lowering and/orlifting of the rear portion of the housing 13.

[0040] Advantageously, the crank 22 is provided, at the front, with agraduated scale, not shown in the figures for the sake of simplicity,which indicates the extent of the vertical movement imparted to the rearportion of the housing 13 as a function of the angular movement impartedto the crank 22, so as to know, on the basis of the height of the wheels16, how much the crank 22 must be turned to bring the housing 13 to atrim in which it is substantially horizontal with respect to the ground.

[0041] In practice, it has been observed that the present invention hasachieved the intended aim and objects.

[0042] An apparatus for adjusting the height of a tool such as alawnmower or the like, particularly for gardening vehicles, has in factbeen provided that has a simple structure and can be used easily andrapidly even by users lacking particular technical knowledge.

[0043] The apparatus has only two wheels (differently from current ones,which have four), and the height from the ground is adjusted byadjusting only the stems 18 of the wheels and by operating the handwheel28.

[0044] The present invention is susceptible of numerous modificationsand variations, all of which are within the scope of the same inventiveconcept.

[0045] The technical details can be replaced with other technicallyequivalent elements.

[0046] The materials, so long as they are compatible with the contingentuse, as well as the dimensions, may be any according to requirements.

[0047] The disclosures in Italian Patent Application No. PD2001A000197from which this application claims priority are incorporated herein byreference.

What is claimed is:
 1. An apparatus for adjusting the height of a toolsuch as a lawnmower particularly for gardening vehicles, of the typethat comprises front wheels whose height can be adjusted oncorresponding supports that are rigidly coupled, at the front, to aprotective housing suitable to form a chassis of said tool, furthercomprising: a rear linkage, which is articulated in a lower region withrespect to said protective housing of the tool, a crank whose length canbe adjusted by a user, said crank being arranged above the housing alongthe tool advancement direction, with a front end that is articulated inan upper region with respect to said housing and a rear end that isarticulated to an upper end of said rear linkage; said linkage beingrigidly coupled to a support that is articulated to the chassis of saidvehicle, articulation points of said linkage and said crank and a commonaxis of rotation of said wheels providing joints of an articulatedquadrilateral constituted by said housing, said linkage, said crank andsaid supports.
 2. The apparatus according to claim 1, wherein said crankhas a front end, which is associated with a first cylindrical joint thatis arranged in front of said housing and above it, and a rear end, whichcan be positioned axially and in an adjustable manner on a secondcylindrical joint that is arranged on the upper end of said linkage. 3.The apparatus according to claim 2, wherein in that said crank has afront end, which is rotatably coupled to said first cylindrical joint ona front upright that rises from said housing, and a rear end, whichengages with a screw-and-nut coupling on said second cylindrical jointarranged on the upper end of said linkage.
 4. The apparatus according toclaim 2, wherein said linkage comprises a lower portion that is shapedsubstantially like an inverted U, with ends that are articulated to thehousing about a substantially horizontal axis, and an upper fork-shapedportion on which said second cylindrical joint is arranged.
 5. Theapparatus according to claim 1, wherein said support is constituted bytwo rod-like elements that are mutually parallel and rigidly coupled andhave front ends that are rigidly coupled to said linkage and rear endsthat are articulated to said vehicle chassis in a lower region.
 6. Theapparatus according to claim 4, wherein two tubular elements protrudemonolithically from said lower region of said linkage, above said endsfor articulation to the housing in the opposite direction with respectto said housing, the front ends of said rod-like elements, which are inturn tubular, engaging on said tubular elements.
 7. The apparatusaccording to claim 1, wherein said crank is provided at a front with ahandwheel that is available to the user.
 8. The apparatus according toclaim 1, wherein said crank is arranged along an advancement directionof said tool, in a substantially central position of said tool.
 9. Theapparatus according to claim 1, wherein said crank has, at a front, agraduated scale that indicates the extent of the vertical movementimparted to the rear portion of said housing as a function of theangular movement imparted to the crank.